Leonard d



UNITED STATES PATENT OEEIcE.

LEONARD D. HOSFORD, OF BROOKLYN, NEV YORK.

PROCESS OF ELECTROPLATING LEAD PIPES.

SPECIFICATION forming part of Letters Patent No. 403,429, dated May 14, 1889. Application filed March 12, 1888. Serial No. 266,978. (No specimens.)

To all whom it may concern.-

Be it known that I, LEONARD D. HOSFORD, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in the Process of Electroplating Lead Pipes, of which the following is a specification.

This invention relates to the manufacture of pipes used in plumbing-such, for example, as the flush-pipes of water-closets, the service-pipes leading to tanks, faucets, &c., the waste-pipes from basins, sinks, and urinals, and the soil-pipes leading from waterclosets-and to traps or water seals in or connected with these several pipes.

The object of my invention is to provide a kind or construction of piping for use in plumbing which shall combine the advantages of lead pipes with those of brass or copper pipes, and shall be subject in the minimum degree to the disadvantages of each.

To this end my invention provides a pipe with a body portion or interior of lead and an exterior of brass or other alloy of copper such as bronzeor of pure copper. Such a pipe possesses all the advantages inherent in lead pipes, in that it can be easily bent, soldered, and otherwise worked by any ordinary plumber; in that wiped joints may be employed, as is customary with lead pipes, and in that it is not affected by corrosive substances, such as prove troublesome in the use of brass or copper pipes.

The exterior coating applied to the lead pipe or trap is of a harder and tougher metal than lead, and is applied in such manner as to render it strongly adherent thereto, so that it shall be in all essential respects integral therewith. I apply this adherent exterior coating by electro-deposition in the manner which I will hereinafter describe.

The exterior coating is applied according to my invention by means of electro-deposition upon the surface of the previously made and prepared lead pipe or trap, as by this means, in spite of some degree of difficulty attending the operation, the best and most satisfactory results are secured.

In order to enable those skilled in the art of electroplating to practice my invention, I will proceed to describe the preferred method of applying the exterior coating by this means.

The lead pipe must first be rendered chemically clean on its exterior surface, which is .done by scouring it in a solution of caustic potash, and afterward immersing it in a men cury dip in order to amalgamate its surface.

If the pipe is to be plated with pure copper, the solution is prepared by adding to a sulphate -ofcopper solution sufficient ammonia to neutralize it, whereupon the copper will be precipitated, after which the liquid is drained and the precipitate washed repeatedly until all acid is removed. Then an alkaline solution is to be added, preferably a solution of cyanide of potassium, which will dissolve the precipitated copper and yield an alkaline-cyanide copper-plating solution, in which the plating is done. The operation of electroplating is in other respects conducted in the usual manner well known to those skilled in the art of electroplating. It is preferable, however, to plate the pipes with an alloy of copper instead of the pure copper, as thereby is produced a pipe which on its exterior is essentially a brass pipe, and which in many respects is preferable to a copper pipe for the purposes for which my invention is designed. The coating of a pipe exteriorly with a brass or bronze alloy constitutes an additional feature of my invention. The particular solution to be used will depend upon the particular alloy with which it is desired to coat the pipe, and to enable those skilled in the art of electroplating to carry into practice this feature of my invention I will describe means for so coating the pipe with one alloy of this character.

To plate with a coating of yellow brass, a mixed solution of sulphate of copper and sulphate of' zinc with a small proportion of sulphate of arsenic is to be used. The relative proportions will depend upon the precise alloy of which it is desired that the exterior coating shall be formed. A suitable proportion will consist of from three-quarters of sulphate of copper and one-quarter of sulphate of zinc to two-thirds of sulphate of copper and onethird of sulphate of zinc, by weight, to which about five per cent. of sulphate of arsenic will be added.

The most important desideratum in electroplating, and the one with which the most difficulty is liable to be experienced, is in the cleaning of the surface of the lead. If this operation be properly and thoroughly done and the plating performed immediately afterward, no other difficulty will be experienced which cannot be overcome by any skilled electroplater. After the plating operation is performed the surface of the electro-deposited coating is to be finished by polishing or bufE-. ing in the Well-known manner, whereby the pipe is given a bright and smooth surface.

If the process of plating be practiced carefully, as hereinbefore indicated, the exterior coating of brass or brass alloy will be dense, tough, of uniform thickness, and strongly adherent, so that it cannot chip or scale off upon the bending of the pipe or upon the latter being subjected to blows, or by any ordinary abrasive action to which a lead pipe is liable to be subjected. The pipe can be connected by means of wiped joints in the ordinary manner and by any reasonably skilled plumber, who will encounter no other difficulty than is found in the joining-up of ordinary lead pipes. The pipe can be bent to any desired curve in the same manner and with the same case as ordinary lead pipes and with as little liability of injury. It has the same sanitary advantages as respects insensibility to the corrosive action of the fluids passing through it as are possessed by lead pipe generally, and externally it is to all appearance a brass or copper pipe, and has the same advantages in all respects that. pipes of those metals possess.

I make no claim in this application to the product of myprocessnamely, to aplu mbers pipe or trap consisting of an inner body por tion of lead and a thin adherent exterior coating of copper, brass, or other alloy or other relatively hard and tough metal, applied either by electro-deposition or other- Wiseas such product is claimed in my application, Serial No. 307,923, filed April 20, 1889, which is a division of my present application.

What I claim, and desire to secure by Let ters Patent, is

The process of making plumbers pipes having an exterior coating of a denser and tougher metal, consisting in taking a, lead pipe, rendering its exterior surface chemically clean by scouring it,'immersing in a solution of caustic alkali and afterward immersing it in a mercury-dip, and subsequently electroplating said pipe in a bath consisting of a solution of the salt of the metal to be deposited.

In witness whereof I have hereunto signed my name inthepr'esence of two subscribing witnesses.

LEONARD 1). HOSFORD.

Witnesses:

J NO. E. GAVIN, ARTHUR O. FRASER. 

